I'm not what you'd call a science fiction geek, so thank goodness enough of you are out there to help me understand my current favorite show.

I'm talking about Sci-Fi Channel's "Battlestar Galactica," reimagined from the relatively lightweight 1978 series and now in its fourth and final season.

The ongoing quest for planet Earth by fewer than 40,000 survivors of a devastating Cylon attack took a shocking turn at the end of last season. We found out that four of the Battlestar crew, patriotic Cylon-haters all, were actually Cylons -- part of "the final five" of 12 human-looking models, of which seven were previously known.

Now, we're waiting to find out the identity of that fifth Cylon -- possibly on Friday.

The writers keep teasing us with little clues, and it's driving fans crazy.

"It's all very confusing," says Susan Vanderweert, a lawyer from Raleigh.

She has theories, and when Vanderweert talks, I listen.

After all, she was one of the first people to tell me last year that Kara "Starbuck" Thrace wasn't really dead after her ship exploded, so props for that.

She also correctly guessed that Starbuck's ex, Sam Anders, was a Cylon. The others, revealed at the end of season three, are Col. Tigh, Chief Tyrol and Tory, President Laura Roslin's sexy (and dangerous) aide.

So now, we're trading guesses about the fifth one. Of course, the writers don't want to make it too obvious, so how about officer Karl "Helo" Agathon?

After all, he's married to a Cylon -- Sharon -- whose exact copy was previously with Chief Tyrol, also a Cylon. Juicy, huh?

Vanderweert has another idea.

"I think it's maybe Roslin," she bravely ventures.

Yeah, I counter, but Roslin is dying of cancer.

"Maybe she's the ultimate Cylon," Vanderweert says. "Maybe the ultimate Cylon is such a fine mix of human and Cylon that they can actually die."

I admit that it flashed in my head this season that Roslin could be a Cylon. Roslin had taken a compulsive shot at Starbuck, missing her by inches, after Starbuck provoked her. Vanderweert points instead to a scene last season in which Sharon, Cylon model Six and Roslin all shared the exact same dream, which involved Sharon's baby and the final five.

"I think Roslin would be an interesting choice," Vanderweert says.

I mentioned that Starbuck is still a possibility, though maybe too obvious. She seems to have an uncanny instinct about setting a course for planet Earth that comes from knowledge seemingly ingrained in her from childhood.

"I still think that she might be one of the first 'skin-jobs,'" Vanderweert says, using the "Battlestar" slang for Cylons who look like humans, as opposed to the robotic steel "toasters."

"We never found out who her father is," Vanderweert continues. "We only know that her mother had these mixed, bitter, love/hate feelings for Kara, so that's why I was thinking that maybe her mother was somehow impregnated by a Cylon."

Here's where it gets really complicated.

"But, of course, that would make her not one of 'the five,'" she says, "but one of the first Cylon/human mixes, just like Helo and Sharon's baby."

Unless, of course, Helo is a Cylon. D'oh!

Then there's always narcissistic, sex-mad scientist Gaius Baltar, who stupidly aided Six in the near-destruction of the human race. Vanderweert thinks he fits some of the traits of the later, less logical, more emotional Cylon models -- the ability to fall in love, for instance.

"They've been flirting with that idea for seasons now," Vanderweert points out. "It would make sense, in some ways, because he is just about the most flawed human being -- brilliant but emotionally crippled."

So what do you think, "Battlestar" geeks? Help me out here!